Individuals diagnosed with major depression are characterized by reduced responsivity to reward, as evidenced by both subjective report and behavioral functioning. The proposed research tests a formulation in which the decreased responsiveness of depressed individuals to rewarding stimuli are conceptualized as reflecting lower levels of Behavioral Activation System (BAS) functioning. The primary aim of the proposed study is to examine comprehensively BAS functioning in depressed individuals as measured by subjective report, behavioral performance, autonomic reactivity, and neural activation. More specifically, it is hypothesized that, relative to healthy controls, depressed individuals will exhibit reduced BAS functioning during reward anticipation and outcome. A secondary aim of this study is to evaluate Behavioral Inhibition System (BIS) functioning in depressed individuals in response to the anticipation and outcome of punishment. This second component of the proposed research is the first of its kind; although there is a paucity of theoretical and empirical evidence concerning BIS functioning in depression, it is hypothesized that depressed individuals will demonstrate elevated levels of BIS functioning while anticipating and receiving punishment. Finally, by examining individuals longitudinally, both while they are depressed and again following recovery, the proposed study aims to assess the relative roles of the behavioral activation and inhibition systems in affecting the long-term course of depressive illness. [unreadable] [unreadable]